One type of power transmission system includes a set of pulleys coupled together and rotated by a power transmission belt such as a V-belt. The V-belt transfers power between pulleys via friction, where the friction is multiplied by the mechanical advantage of the wedging principle. Correct V-belt operation is dependent on proper tension of the V-belt, though there is a wide range of tension in which a V-belt may correctly operate. For example, an under-tensioned V-belt may slip within a pulley groove, which may generate excess heat and result in premature wear of the V-belt, pulleys, or bearings within the pulleys. By way of another example, an over-tensioned V-belt may result in excess stress on the V-belt, pulleys, bearings within the pulleys, and/or shafts connected to the pulleys.
A variety of factors may need to be considered when tensioning a V-belt. For example, the V-belt may include a variety or sub-variety of V-belt, where each variety and/or sub-variety of V-belt is fabricated from different exterior materials and/or different interior tension cables. For instance, the variety or sub-variety of V-belt may include, but are not limited to, a classical V-belt, a wedge V-belt, a Kevlar V-belt, or the like. By way of another example, the V-belt may be utilized with a pulley of a particular diameter. By way of another example, the V-belt may be utilized in an application requiring a particular rotation per minute (RPM) operating speed. By way of another example, the V-belt may include a new V-belt or a used V-belt. By way of another example, the V-belt may include an unmolded construction, a cogged construction, a ribbed construction, or the like.
As such, tension in a V-belt is difficult to measure. For example, measuring “by feel” may result in a tensioning that is typically only between 7% and 50% of proper tensioning. By way of another example, measuring via devices currently known in the art may result in severe over-tensioning in the range of 150% to 250%. By way of another example, measuring via a Force-Deflection method requires a time-intensive method involving looking up numbers in a table or using a computer calculation, increasing downtime and resulting in lost revenue.
The Force-Deflection method includes measuring a span length P (e.g., the distance between the centers of two pulleys) and applying a force F (e.g., using a belt tension gauge) perpendicular to the belt span P at a center point C. In Imperial or SAE units, the force F is selected to generate an amount of belt deflection q determined from deflecting the belt 1/64 inch for every 1 inch of belt span P (e.g., q= 1/64*P). For example, where P is 32 inches, q is 32/64 inches, or ½ inch. One source of values for the force F is a table equating force values to one or more of small pulley diameter range, RPM range, cog states, and/or previous amount of belt use. It is noted herein, however, that force tables generally include the force F on a per-rib basis, such that the force F is multiplied per the number of ribs on the V-belt. For example, where the V-belt has five ribs, the force F provided in the table is multiplied by five.
Incorrect installation procedures may lead to shortened V-belt life. For example, a V-belt that has been “rolled on” may be under-tensioned, resulting in decreased V-belt life due to belt slip and heat build-up. By way of another example, cables within a V-belt that has been “stretched on” may be damaged by a prying motion during installation, which may lead to early V-belt failure. By way of another example, a worn V-belt may be over-tensioned if installed at the same tension as a new V-belt.
Between 50% and 70% of tension in a V-belt may be lost over time. For example, V-belt tension may decrease within the first hour of use as the belt settles in a pulley groove. In this regard, a V-belt may need be initially be over-tensioned during installation to compensate for the loss of tension during the break-in period of the V-belt, otherwise the V-belt may ultimately be under-tensioned which may lead to a shortened V-belt life. By way of another example, tension in the V-belt may decrease as the V-belt stretches during the course of its life.
Therefore, it would be advantageous to provide a system and method that overcomes the shortcomings described above.